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	 54e9912428
			
		
	
	
		54e9912428
		
	
	
	
	
		
			
			Impact: fix hung task with certain (non-default) rt-limit settings Corey Hickey reported that on using setuid to change the uid of a rt process, the process would be unkillable and not be running. This is because there was no rt runtime for that user group. Add in a check to see if a user can attach an rt task to its task group. On failure, return EINVAL, which is also returned in CONFIG_CGROUP_SCHED. Reported-by: Corey Hickey <bugfood-ml@fatooh.org> Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
		
			
				
	
	
		
			1889 lines
		
	
	
	
		
			42 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			1889 lines
		
	
	
	
		
			42 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  *  linux/kernel/sys.c
 | |
|  *
 | |
|  *  Copyright (C) 1991, 1992  Linus Torvalds
 | |
|  */
 | |
| 
 | |
| #include <linux/module.h>
 | |
| #include <linux/mm.h>
 | |
| #include <linux/utsname.h>
 | |
| #include <linux/mman.h>
 | |
| #include <linux/smp_lock.h>
 | |
| #include <linux/notifier.h>
 | |
| #include <linux/reboot.h>
 | |
| #include <linux/prctl.h>
 | |
| #include <linux/highuid.h>
 | |
| #include <linux/fs.h>
 | |
| #include <linux/resource.h>
 | |
| #include <linux/kernel.h>
 | |
| #include <linux/kexec.h>
 | |
| #include <linux/workqueue.h>
 | |
| #include <linux/capability.h>
 | |
| #include <linux/device.h>
 | |
| #include <linux/key.h>
 | |
| #include <linux/times.h>
 | |
| #include <linux/posix-timers.h>
 | |
| #include <linux/security.h>
 | |
| #include <linux/dcookies.h>
 | |
| #include <linux/suspend.h>
 | |
| #include <linux/tty.h>
 | |
| #include <linux/signal.h>
 | |
| #include <linux/cn_proc.h>
 | |
| #include <linux/getcpu.h>
 | |
| #include <linux/task_io_accounting_ops.h>
 | |
| #include <linux/seccomp.h>
 | |
| #include <linux/cpu.h>
 | |
| #include <linux/ptrace.h>
 | |
| 
 | |
| #include <linux/compat.h>
 | |
| #include <linux/syscalls.h>
 | |
| #include <linux/kprobes.h>
 | |
| #include <linux/user_namespace.h>
 | |
| 
 | |
| #include <asm/uaccess.h>
 | |
| #include <asm/io.h>
 | |
| #include <asm/unistd.h>
 | |
| 
 | |
| #ifndef SET_UNALIGN_CTL
 | |
| # define SET_UNALIGN_CTL(a,b)	(-EINVAL)
 | |
| #endif
 | |
| #ifndef GET_UNALIGN_CTL
 | |
| # define GET_UNALIGN_CTL(a,b)	(-EINVAL)
 | |
| #endif
 | |
| #ifndef SET_FPEMU_CTL
 | |
| # define SET_FPEMU_CTL(a,b)	(-EINVAL)
 | |
| #endif
 | |
| #ifndef GET_FPEMU_CTL
 | |
| # define GET_FPEMU_CTL(a,b)	(-EINVAL)
 | |
| #endif
 | |
| #ifndef SET_FPEXC_CTL
 | |
| # define SET_FPEXC_CTL(a,b)	(-EINVAL)
 | |
| #endif
 | |
| #ifndef GET_FPEXC_CTL
 | |
| # define GET_FPEXC_CTL(a,b)	(-EINVAL)
 | |
| #endif
 | |
| #ifndef GET_ENDIAN
 | |
| # define GET_ENDIAN(a,b)	(-EINVAL)
 | |
| #endif
 | |
| #ifndef SET_ENDIAN
 | |
| # define SET_ENDIAN(a,b)	(-EINVAL)
 | |
| #endif
 | |
| #ifndef GET_TSC_CTL
 | |
| # define GET_TSC_CTL(a)		(-EINVAL)
 | |
| #endif
 | |
| #ifndef SET_TSC_CTL
 | |
| # define SET_TSC_CTL(a)		(-EINVAL)
 | |
| #endif
 | |
| 
 | |
| /*
 | |
|  * this is where the system-wide overflow UID and GID are defined, for
 | |
|  * architectures that now have 32-bit UID/GID but didn't in the past
 | |
|  */
 | |
| 
 | |
| int overflowuid = DEFAULT_OVERFLOWUID;
 | |
| int overflowgid = DEFAULT_OVERFLOWGID;
 | |
| 
 | |
| #ifdef CONFIG_UID16
 | |
| EXPORT_SYMBOL(overflowuid);
 | |
| EXPORT_SYMBOL(overflowgid);
 | |
| #endif
 | |
| 
 | |
| /*
 | |
|  * the same as above, but for filesystems which can only store a 16-bit
 | |
|  * UID and GID. as such, this is needed on all architectures
 | |
|  */
 | |
| 
 | |
| int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
 | |
| int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
 | |
| 
 | |
| EXPORT_SYMBOL(fs_overflowuid);
 | |
| EXPORT_SYMBOL(fs_overflowgid);
 | |
| 
 | |
| /*
 | |
|  * this indicates whether you can reboot with ctrl-alt-del: the default is yes
 | |
|  */
 | |
| 
 | |
| int C_A_D = 1;
 | |
| struct pid *cad_pid;
 | |
| EXPORT_SYMBOL(cad_pid);
 | |
| 
 | |
| /*
 | |
|  * If set, this is used for preparing the system to power off.
 | |
|  */
 | |
| 
 | |
| void (*pm_power_off_prepare)(void);
 | |
| 
 | |
| /*
 | |
|  * set the priority of a task
 | |
|  * - the caller must hold the RCU read lock
 | |
|  */
 | |
| static int set_one_prio(struct task_struct *p, int niceval, int error)
 | |
| {
 | |
| 	const struct cred *cred = current_cred(), *pcred = __task_cred(p);
 | |
| 	int no_nice;
 | |
| 
 | |
| 	if (pcred->uid  != cred->euid &&
 | |
| 	    pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) {
 | |
| 		error = -EPERM;
 | |
| 		goto out;
 | |
| 	}
 | |
| 	if (niceval < task_nice(p) && !can_nice(p, niceval)) {
 | |
| 		error = -EACCES;
 | |
| 		goto out;
 | |
| 	}
 | |
| 	no_nice = security_task_setnice(p, niceval);
 | |
| 	if (no_nice) {
 | |
| 		error = no_nice;
 | |
| 		goto out;
 | |
| 	}
 | |
| 	if (error == -ESRCH)
 | |
| 		error = 0;
 | |
| 	set_user_nice(p, niceval);
 | |
| out:
 | |
| 	return error;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
 | |
| {
 | |
| 	struct task_struct *g, *p;
 | |
| 	struct user_struct *user;
 | |
| 	const struct cred *cred = current_cred();
 | |
| 	int error = -EINVAL;
 | |
| 	struct pid *pgrp;
 | |
| 
 | |
| 	if (which > PRIO_USER || which < PRIO_PROCESS)
 | |
| 		goto out;
 | |
| 
 | |
| 	/* normalize: avoid signed division (rounding problems) */
 | |
| 	error = -ESRCH;
 | |
| 	if (niceval < -20)
 | |
| 		niceval = -20;
 | |
| 	if (niceval > 19)
 | |
| 		niceval = 19;
 | |
| 
 | |
| 	read_lock(&tasklist_lock);
 | |
| 	switch (which) {
 | |
| 		case PRIO_PROCESS:
 | |
| 			if (who)
 | |
| 				p = find_task_by_vpid(who);
 | |
| 			else
 | |
| 				p = current;
 | |
| 			if (p)
 | |
| 				error = set_one_prio(p, niceval, error);
 | |
| 			break;
 | |
| 		case PRIO_PGRP:
 | |
| 			if (who)
 | |
| 				pgrp = find_vpid(who);
 | |
| 			else
 | |
| 				pgrp = task_pgrp(current);
 | |
| 			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 | |
| 				error = set_one_prio(p, niceval, error);
 | |
| 			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 | |
| 			break;
 | |
| 		case PRIO_USER:
 | |
| 			user = (struct user_struct *) cred->user;
 | |
| 			if (!who)
 | |
| 				who = cred->uid;
 | |
| 			else if ((who != cred->uid) &&
 | |
| 				 !(user = find_user(who)))
 | |
| 				goto out_unlock;	/* No processes for this user */
 | |
| 
 | |
| 			do_each_thread(g, p)
 | |
| 				if (__task_cred(p)->uid == who)
 | |
| 					error = set_one_prio(p, niceval, error);
 | |
| 			while_each_thread(g, p);
 | |
| 			if (who != cred->uid)
 | |
| 				free_uid(user);		/* For find_user() */
 | |
| 			break;
 | |
| 	}
 | |
| out_unlock:
 | |
| 	read_unlock(&tasklist_lock);
 | |
| out:
 | |
| 	return error;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Ugh. To avoid negative return values, "getpriority()" will
 | |
|  * not return the normal nice-value, but a negated value that
 | |
|  * has been offset by 20 (ie it returns 40..1 instead of -20..19)
 | |
|  * to stay compatible.
 | |
|  */
 | |
| SYSCALL_DEFINE2(getpriority, int, which, int, who)
 | |
| {
 | |
| 	struct task_struct *g, *p;
 | |
| 	struct user_struct *user;
 | |
| 	const struct cred *cred = current_cred();
 | |
| 	long niceval, retval = -ESRCH;
 | |
| 	struct pid *pgrp;
 | |
| 
 | |
| 	if (which > PRIO_USER || which < PRIO_PROCESS)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	read_lock(&tasklist_lock);
 | |
| 	switch (which) {
 | |
| 		case PRIO_PROCESS:
 | |
| 			if (who)
 | |
| 				p = find_task_by_vpid(who);
 | |
| 			else
 | |
| 				p = current;
 | |
| 			if (p) {
 | |
| 				niceval = 20 - task_nice(p);
 | |
| 				if (niceval > retval)
 | |
| 					retval = niceval;
 | |
| 			}
 | |
| 			break;
 | |
| 		case PRIO_PGRP:
 | |
| 			if (who)
 | |
| 				pgrp = find_vpid(who);
 | |
| 			else
 | |
| 				pgrp = task_pgrp(current);
 | |
| 			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
 | |
| 				niceval = 20 - task_nice(p);
 | |
| 				if (niceval > retval)
 | |
| 					retval = niceval;
 | |
| 			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
 | |
| 			break;
 | |
| 		case PRIO_USER:
 | |
| 			user = (struct user_struct *) cred->user;
 | |
| 			if (!who)
 | |
| 				who = cred->uid;
 | |
| 			else if ((who != cred->uid) &&
 | |
| 				 !(user = find_user(who)))
 | |
| 				goto out_unlock;	/* No processes for this user */
 | |
| 
 | |
| 			do_each_thread(g, p)
 | |
| 				if (__task_cred(p)->uid == who) {
 | |
| 					niceval = 20 - task_nice(p);
 | |
| 					if (niceval > retval)
 | |
| 						retval = niceval;
 | |
| 				}
 | |
| 			while_each_thread(g, p);
 | |
| 			if (who != cred->uid)
 | |
| 				free_uid(user);		/* for find_user() */
 | |
| 			break;
 | |
| 	}
 | |
| out_unlock:
 | |
| 	read_unlock(&tasklist_lock);
 | |
| 
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	emergency_restart - reboot the system
 | |
|  *
 | |
|  *	Without shutting down any hardware or taking any locks
 | |
|  *	reboot the system.  This is called when we know we are in
 | |
|  *	trouble so this is our best effort to reboot.  This is
 | |
|  *	safe to call in interrupt context.
 | |
|  */
 | |
| void emergency_restart(void)
 | |
| {
 | |
| 	machine_emergency_restart();
 | |
| }
 | |
| EXPORT_SYMBOL_GPL(emergency_restart);
 | |
| 
 | |
| void kernel_restart_prepare(char *cmd)
 | |
| {
 | |
| 	blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
 | |
| 	system_state = SYSTEM_RESTART;
 | |
| 	device_shutdown();
 | |
| 	sysdev_shutdown();
 | |
| }
 | |
| 
 | |
| /**
 | |
|  *	kernel_restart - reboot the system
 | |
|  *	@cmd: pointer to buffer containing command to execute for restart
 | |
|  *		or %NULL
 | |
|  *
 | |
|  *	Shutdown everything and perform a clean reboot.
 | |
|  *	This is not safe to call in interrupt context.
 | |
|  */
 | |
| void kernel_restart(char *cmd)
 | |
| {
 | |
| 	kernel_restart_prepare(cmd);
 | |
| 	if (!cmd)
 | |
| 		printk(KERN_EMERG "Restarting system.\n");
 | |
| 	else
 | |
| 		printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
 | |
| 	machine_restart(cmd);
 | |
| }
 | |
| EXPORT_SYMBOL_GPL(kernel_restart);
 | |
| 
 | |
| static void kernel_shutdown_prepare(enum system_states state)
 | |
| {
 | |
| 	blocking_notifier_call_chain(&reboot_notifier_list,
 | |
| 		(state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
 | |
| 	system_state = state;
 | |
| 	device_shutdown();
 | |
| }
 | |
| /**
 | |
|  *	kernel_halt - halt the system
 | |
|  *
 | |
|  *	Shutdown everything and perform a clean system halt.
 | |
|  */
 | |
| void kernel_halt(void)
 | |
| {
 | |
| 	kernel_shutdown_prepare(SYSTEM_HALT);
 | |
| 	sysdev_shutdown();
 | |
| 	printk(KERN_EMERG "System halted.\n");
 | |
| 	machine_halt();
 | |
| }
 | |
| 
 | |
| EXPORT_SYMBOL_GPL(kernel_halt);
 | |
| 
 | |
| /**
 | |
|  *	kernel_power_off - power_off the system
 | |
|  *
 | |
|  *	Shutdown everything and perform a clean system power_off.
 | |
|  */
 | |
| void kernel_power_off(void)
 | |
| {
 | |
| 	kernel_shutdown_prepare(SYSTEM_POWER_OFF);
 | |
| 	if (pm_power_off_prepare)
 | |
| 		pm_power_off_prepare();
 | |
| 	disable_nonboot_cpus();
 | |
| 	sysdev_shutdown();
 | |
| 	printk(KERN_EMERG "Power down.\n");
 | |
| 	machine_power_off();
 | |
| }
 | |
| EXPORT_SYMBOL_GPL(kernel_power_off);
 | |
| /*
 | |
|  * Reboot system call: for obvious reasons only root may call it,
 | |
|  * and even root needs to set up some magic numbers in the registers
 | |
|  * so that some mistake won't make this reboot the whole machine.
 | |
|  * You can also set the meaning of the ctrl-alt-del-key here.
 | |
|  *
 | |
|  * reboot doesn't sync: do that yourself before calling this.
 | |
|  */
 | |
| SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
 | |
| 		void __user *, arg)
 | |
| {
 | |
| 	char buffer[256];
 | |
| 
 | |
| 	/* We only trust the superuser with rebooting the system. */
 | |
| 	if (!capable(CAP_SYS_BOOT))
 | |
| 		return -EPERM;
 | |
| 
 | |
| 	/* For safety, we require "magic" arguments. */
 | |
| 	if (magic1 != LINUX_REBOOT_MAGIC1 ||
 | |
| 	    (magic2 != LINUX_REBOOT_MAGIC2 &&
 | |
| 	                magic2 != LINUX_REBOOT_MAGIC2A &&
 | |
| 			magic2 != LINUX_REBOOT_MAGIC2B &&
 | |
| 	                magic2 != LINUX_REBOOT_MAGIC2C))
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	/* Instead of trying to make the power_off code look like
 | |
| 	 * halt when pm_power_off is not set do it the easy way.
 | |
| 	 */
 | |
| 	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
 | |
| 		cmd = LINUX_REBOOT_CMD_HALT;
 | |
| 
 | |
| 	lock_kernel();
 | |
| 	switch (cmd) {
 | |
| 	case LINUX_REBOOT_CMD_RESTART:
 | |
| 		kernel_restart(NULL);
 | |
| 		break;
 | |
| 
 | |
| 	case LINUX_REBOOT_CMD_CAD_ON:
 | |
| 		C_A_D = 1;
 | |
| 		break;
 | |
| 
 | |
| 	case LINUX_REBOOT_CMD_CAD_OFF:
 | |
| 		C_A_D = 0;
 | |
| 		break;
 | |
| 
 | |
| 	case LINUX_REBOOT_CMD_HALT:
 | |
| 		kernel_halt();
 | |
| 		unlock_kernel();
 | |
| 		do_exit(0);
 | |
| 		break;
 | |
| 
 | |
| 	case LINUX_REBOOT_CMD_POWER_OFF:
 | |
| 		kernel_power_off();
 | |
| 		unlock_kernel();
 | |
| 		do_exit(0);
 | |
| 		break;
 | |
| 
 | |
| 	case LINUX_REBOOT_CMD_RESTART2:
 | |
| 		if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
 | |
| 			unlock_kernel();
 | |
| 			return -EFAULT;
 | |
| 		}
 | |
| 		buffer[sizeof(buffer) - 1] = '\0';
 | |
| 
 | |
| 		kernel_restart(buffer);
 | |
| 		break;
 | |
| 
 | |
| #ifdef CONFIG_KEXEC
 | |
| 	case LINUX_REBOOT_CMD_KEXEC:
 | |
| 		{
 | |
| 			int ret;
 | |
| 			ret = kernel_kexec();
 | |
| 			unlock_kernel();
 | |
| 			return ret;
 | |
| 		}
 | |
| #endif
 | |
| 
 | |
| #ifdef CONFIG_HIBERNATION
 | |
| 	case LINUX_REBOOT_CMD_SW_SUSPEND:
 | |
| 		{
 | |
| 			int ret = hibernate();
 | |
| 			unlock_kernel();
 | |
| 			return ret;
 | |
| 		}
 | |
| #endif
 | |
| 
 | |
| 	default:
 | |
| 		unlock_kernel();
 | |
| 		return -EINVAL;
 | |
| 	}
 | |
| 	unlock_kernel();
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static void deferred_cad(struct work_struct *dummy)
 | |
| {
 | |
| 	kernel_restart(NULL);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
 | |
|  * As it's called within an interrupt, it may NOT sync: the only choice
 | |
|  * is whether to reboot at once, or just ignore the ctrl-alt-del.
 | |
|  */
 | |
| void ctrl_alt_del(void)
 | |
| {
 | |
| 	static DECLARE_WORK(cad_work, deferred_cad);
 | |
| 
 | |
| 	if (C_A_D)
 | |
| 		schedule_work(&cad_work);
 | |
| 	else
 | |
| 		kill_cad_pid(SIGINT, 1);
 | |
| }
 | |
| 	
 | |
| /*
 | |
|  * Unprivileged users may change the real gid to the effective gid
 | |
|  * or vice versa.  (BSD-style)
 | |
|  *
 | |
|  * If you set the real gid at all, or set the effective gid to a value not
 | |
|  * equal to the real gid, then the saved gid is set to the new effective gid.
 | |
|  *
 | |
|  * This makes it possible for a setgid program to completely drop its
 | |
|  * privileges, which is often a useful assertion to make when you are doing
 | |
|  * a security audit over a program.
 | |
|  *
 | |
|  * The general idea is that a program which uses just setregid() will be
 | |
|  * 100% compatible with BSD.  A program which uses just setgid() will be
 | |
|  * 100% compatible with POSIX with saved IDs. 
 | |
|  *
 | |
|  * SMP: There are not races, the GIDs are checked only by filesystem
 | |
|  *      operations (as far as semantic preservation is concerned).
 | |
|  */
 | |
| SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
 | |
| {
 | |
| 	const struct cred *old;
 | |
| 	struct cred *new;
 | |
| 	int retval;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return -ENOMEM;
 | |
| 	old = current_cred();
 | |
| 
 | |
| 	retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
 | |
| 	if (retval)
 | |
| 		goto error;
 | |
| 
 | |
| 	retval = -EPERM;
 | |
| 	if (rgid != (gid_t) -1) {
 | |
| 		if (old->gid == rgid ||
 | |
| 		    old->egid == rgid ||
 | |
| 		    capable(CAP_SETGID))
 | |
| 			new->gid = rgid;
 | |
| 		else
 | |
| 			goto error;
 | |
| 	}
 | |
| 	if (egid != (gid_t) -1) {
 | |
| 		if (old->gid == egid ||
 | |
| 		    old->egid == egid ||
 | |
| 		    old->sgid == egid ||
 | |
| 		    capable(CAP_SETGID))
 | |
| 			new->egid = egid;
 | |
| 		else
 | |
| 			goto error;
 | |
| 	}
 | |
| 
 | |
| 	if (rgid != (gid_t) -1 ||
 | |
| 	    (egid != (gid_t) -1 && egid != old->gid))
 | |
| 		new->sgid = new->egid;
 | |
| 	new->fsgid = new->egid;
 | |
| 
 | |
| 	return commit_creds(new);
 | |
| 
 | |
| error:
 | |
| 	abort_creds(new);
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * setgid() is implemented like SysV w/ SAVED_IDS 
 | |
|  *
 | |
|  * SMP: Same implicit races as above.
 | |
|  */
 | |
| SYSCALL_DEFINE1(setgid, gid_t, gid)
 | |
| {
 | |
| 	const struct cred *old;
 | |
| 	struct cred *new;
 | |
| 	int retval;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return -ENOMEM;
 | |
| 	old = current_cred();
 | |
| 
 | |
| 	retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
 | |
| 	if (retval)
 | |
| 		goto error;
 | |
| 
 | |
| 	retval = -EPERM;
 | |
| 	if (capable(CAP_SETGID))
 | |
| 		new->gid = new->egid = new->sgid = new->fsgid = gid;
 | |
| 	else if (gid == old->gid || gid == old->sgid)
 | |
| 		new->egid = new->fsgid = gid;
 | |
| 	else
 | |
| 		goto error;
 | |
| 
 | |
| 	return commit_creds(new);
 | |
| 
 | |
| error:
 | |
| 	abort_creds(new);
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * change the user struct in a credentials set to match the new UID
 | |
|  */
 | |
| static int set_user(struct cred *new)
 | |
| {
 | |
| 	struct user_struct *new_user;
 | |
| 
 | |
| 	new_user = alloc_uid(current_user_ns(), new->uid);
 | |
| 	if (!new_user)
 | |
| 		return -EAGAIN;
 | |
| 
 | |
| 	if (!task_can_switch_user(new_user, current)) {
 | |
| 		free_uid(new_user);
 | |
| 		return -EINVAL;
 | |
| 	}
 | |
| 
 | |
| 	if (atomic_read(&new_user->processes) >=
 | |
| 				current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
 | |
| 			new_user != INIT_USER) {
 | |
| 		free_uid(new_user);
 | |
| 		return -EAGAIN;
 | |
| 	}
 | |
| 
 | |
| 	free_uid(new->user);
 | |
| 	new->user = new_user;
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Unprivileged users may change the real uid to the effective uid
 | |
|  * or vice versa.  (BSD-style)
 | |
|  *
 | |
|  * If you set the real uid at all, or set the effective uid to a value not
 | |
|  * equal to the real uid, then the saved uid is set to the new effective uid.
 | |
|  *
 | |
|  * This makes it possible for a setuid program to completely drop its
 | |
|  * privileges, which is often a useful assertion to make when you are doing
 | |
|  * a security audit over a program.
 | |
|  *
 | |
|  * The general idea is that a program which uses just setreuid() will be
 | |
|  * 100% compatible with BSD.  A program which uses just setuid() will be
 | |
|  * 100% compatible with POSIX with saved IDs. 
 | |
|  */
 | |
| SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
 | |
| {
 | |
| 	const struct cred *old;
 | |
| 	struct cred *new;
 | |
| 	int retval;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return -ENOMEM;
 | |
| 	old = current_cred();
 | |
| 
 | |
| 	retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
 | |
| 	if (retval)
 | |
| 		goto error;
 | |
| 
 | |
| 	retval = -EPERM;
 | |
| 	if (ruid != (uid_t) -1) {
 | |
| 		new->uid = ruid;
 | |
| 		if (old->uid != ruid &&
 | |
| 		    old->euid != ruid &&
 | |
| 		    !capable(CAP_SETUID))
 | |
| 			goto error;
 | |
| 	}
 | |
| 
 | |
| 	if (euid != (uid_t) -1) {
 | |
| 		new->euid = euid;
 | |
| 		if (old->uid != euid &&
 | |
| 		    old->euid != euid &&
 | |
| 		    old->suid != euid &&
 | |
| 		    !capable(CAP_SETUID))
 | |
| 			goto error;
 | |
| 	}
 | |
| 
 | |
| 	if (new->uid != old->uid) {
 | |
| 		retval = set_user(new);
 | |
| 		if (retval < 0)
 | |
| 			goto error;
 | |
| 	}
 | |
| 	if (ruid != (uid_t) -1 ||
 | |
| 	    (euid != (uid_t) -1 && euid != old->uid))
 | |
| 		new->suid = new->euid;
 | |
| 	new->fsuid = new->euid;
 | |
| 
 | |
| 	retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
 | |
| 	if (retval < 0)
 | |
| 		goto error;
 | |
| 
 | |
| 	return commit_creds(new);
 | |
| 
 | |
| error:
 | |
| 	abort_creds(new);
 | |
| 	return retval;
 | |
| }
 | |
| 		
 | |
| /*
 | |
|  * setuid() is implemented like SysV with SAVED_IDS 
 | |
|  * 
 | |
|  * Note that SAVED_ID's is deficient in that a setuid root program
 | |
|  * like sendmail, for example, cannot set its uid to be a normal 
 | |
|  * user and then switch back, because if you're root, setuid() sets
 | |
|  * the saved uid too.  If you don't like this, blame the bright people
 | |
|  * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
 | |
|  * will allow a root program to temporarily drop privileges and be able to
 | |
|  * regain them by swapping the real and effective uid.  
 | |
|  */
 | |
| SYSCALL_DEFINE1(setuid, uid_t, uid)
 | |
| {
 | |
| 	const struct cred *old;
 | |
| 	struct cred *new;
 | |
| 	int retval;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return -ENOMEM;
 | |
| 	old = current_cred();
 | |
| 
 | |
| 	retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
 | |
| 	if (retval)
 | |
| 		goto error;
 | |
| 
 | |
| 	retval = -EPERM;
 | |
| 	if (capable(CAP_SETUID)) {
 | |
| 		new->suid = new->uid = uid;
 | |
| 		if (uid != old->uid) {
 | |
| 			retval = set_user(new);
 | |
| 			if (retval < 0)
 | |
| 				goto error;
 | |
| 		}
 | |
| 	} else if (uid != old->uid && uid != new->suid) {
 | |
| 		goto error;
 | |
| 	}
 | |
| 
 | |
| 	new->fsuid = new->euid = uid;
 | |
| 
 | |
| 	retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
 | |
| 	if (retval < 0)
 | |
| 		goto error;
 | |
| 
 | |
| 	return commit_creds(new);
 | |
| 
 | |
| error:
 | |
| 	abort_creds(new);
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * This function implements a generic ability to update ruid, euid,
 | |
|  * and suid.  This allows you to implement the 4.4 compatible seteuid().
 | |
|  */
 | |
| SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
 | |
| {
 | |
| 	const struct cred *old;
 | |
| 	struct cred *new;
 | |
| 	int retval;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return -ENOMEM;
 | |
| 
 | |
| 	retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
 | |
| 	if (retval)
 | |
| 		goto error;
 | |
| 	old = current_cred();
 | |
| 
 | |
| 	retval = -EPERM;
 | |
| 	if (!capable(CAP_SETUID)) {
 | |
| 		if (ruid != (uid_t) -1 && ruid != old->uid &&
 | |
| 		    ruid != old->euid  && ruid != old->suid)
 | |
| 			goto error;
 | |
| 		if (euid != (uid_t) -1 && euid != old->uid &&
 | |
| 		    euid != old->euid  && euid != old->suid)
 | |
| 			goto error;
 | |
| 		if (suid != (uid_t) -1 && suid != old->uid &&
 | |
| 		    suid != old->euid  && suid != old->suid)
 | |
| 			goto error;
 | |
| 	}
 | |
| 
 | |
| 	if (ruid != (uid_t) -1) {
 | |
| 		new->uid = ruid;
 | |
| 		if (ruid != old->uid) {
 | |
| 			retval = set_user(new);
 | |
| 			if (retval < 0)
 | |
| 				goto error;
 | |
| 		}
 | |
| 	}
 | |
| 	if (euid != (uid_t) -1)
 | |
| 		new->euid = euid;
 | |
| 	if (suid != (uid_t) -1)
 | |
| 		new->suid = suid;
 | |
| 	new->fsuid = new->euid;
 | |
| 
 | |
| 	retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
 | |
| 	if (retval < 0)
 | |
| 		goto error;
 | |
| 
 | |
| 	return commit_creds(new);
 | |
| 
 | |
| error:
 | |
| 	abort_creds(new);
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid)
 | |
| {
 | |
| 	const struct cred *cred = current_cred();
 | |
| 	int retval;
 | |
| 
 | |
| 	if (!(retval   = put_user(cred->uid,  ruid)) &&
 | |
| 	    !(retval   = put_user(cred->euid, euid)))
 | |
| 		retval = put_user(cred->suid, suid);
 | |
| 
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Same as above, but for rgid, egid, sgid.
 | |
|  */
 | |
| SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
 | |
| {
 | |
| 	const struct cred *old;
 | |
| 	struct cred *new;
 | |
| 	int retval;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return -ENOMEM;
 | |
| 	old = current_cred();
 | |
| 
 | |
| 	retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
 | |
| 	if (retval)
 | |
| 		goto error;
 | |
| 
 | |
| 	retval = -EPERM;
 | |
| 	if (!capable(CAP_SETGID)) {
 | |
| 		if (rgid != (gid_t) -1 && rgid != old->gid &&
 | |
| 		    rgid != old->egid  && rgid != old->sgid)
 | |
| 			goto error;
 | |
| 		if (egid != (gid_t) -1 && egid != old->gid &&
 | |
| 		    egid != old->egid  && egid != old->sgid)
 | |
| 			goto error;
 | |
| 		if (sgid != (gid_t) -1 && sgid != old->gid &&
 | |
| 		    sgid != old->egid  && sgid != old->sgid)
 | |
| 			goto error;
 | |
| 	}
 | |
| 
 | |
| 	if (rgid != (gid_t) -1)
 | |
| 		new->gid = rgid;
 | |
| 	if (egid != (gid_t) -1)
 | |
| 		new->egid = egid;
 | |
| 	if (sgid != (gid_t) -1)
 | |
| 		new->sgid = sgid;
 | |
| 	new->fsgid = new->egid;
 | |
| 
 | |
| 	return commit_creds(new);
 | |
| 
 | |
| error:
 | |
| 	abort_creds(new);
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid)
 | |
| {
 | |
| 	const struct cred *cred = current_cred();
 | |
| 	int retval;
 | |
| 
 | |
| 	if (!(retval   = put_user(cred->gid,  rgid)) &&
 | |
| 	    !(retval   = put_user(cred->egid, egid)))
 | |
| 		retval = put_user(cred->sgid, sgid);
 | |
| 
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
 | |
|  * is used for "access()" and for the NFS daemon (letting nfsd stay at
 | |
|  * whatever uid it wants to). It normally shadows "euid", except when
 | |
|  * explicitly set by setfsuid() or for access..
 | |
|  */
 | |
| SYSCALL_DEFINE1(setfsuid, uid_t, uid)
 | |
| {
 | |
| 	const struct cred *old;
 | |
| 	struct cred *new;
 | |
| 	uid_t old_fsuid;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return current_fsuid();
 | |
| 	old = current_cred();
 | |
| 	old_fsuid = old->fsuid;
 | |
| 
 | |
| 	if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS) < 0)
 | |
| 		goto error;
 | |
| 
 | |
| 	if (uid == old->uid  || uid == old->euid  ||
 | |
| 	    uid == old->suid || uid == old->fsuid ||
 | |
| 	    capable(CAP_SETUID)) {
 | |
| 		if (uid != old_fsuid) {
 | |
| 			new->fsuid = uid;
 | |
| 			if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
 | |
| 				goto change_okay;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| error:
 | |
| 	abort_creds(new);
 | |
| 	return old_fsuid;
 | |
| 
 | |
| change_okay:
 | |
| 	commit_creds(new);
 | |
| 	return old_fsuid;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Samma på svenska..
 | |
|  */
 | |
| SYSCALL_DEFINE1(setfsgid, gid_t, gid)
 | |
| {
 | |
| 	const struct cred *old;
 | |
| 	struct cred *new;
 | |
| 	gid_t old_fsgid;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return current_fsgid();
 | |
| 	old = current_cred();
 | |
| 	old_fsgid = old->fsgid;
 | |
| 
 | |
| 	if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
 | |
| 		goto error;
 | |
| 
 | |
| 	if (gid == old->gid  || gid == old->egid  ||
 | |
| 	    gid == old->sgid || gid == old->fsgid ||
 | |
| 	    capable(CAP_SETGID)) {
 | |
| 		if (gid != old_fsgid) {
 | |
| 			new->fsgid = gid;
 | |
| 			goto change_okay;
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| error:
 | |
| 	abort_creds(new);
 | |
| 	return old_fsgid;
 | |
| 
 | |
| change_okay:
 | |
| 	commit_creds(new);
 | |
| 	return old_fsgid;
 | |
| }
 | |
| 
 | |
| void do_sys_times(struct tms *tms)
 | |
| {
 | |
| 	struct task_cputime cputime;
 | |
| 	cputime_t cutime, cstime;
 | |
| 
 | |
| 	thread_group_cputime(current, &cputime);
 | |
| 	spin_lock_irq(¤t->sighand->siglock);
 | |
| 	cutime = current->signal->cutime;
 | |
| 	cstime = current->signal->cstime;
 | |
| 	spin_unlock_irq(¤t->sighand->siglock);
 | |
| 	tms->tms_utime = cputime_to_clock_t(cputime.utime);
 | |
| 	tms->tms_stime = cputime_to_clock_t(cputime.stime);
 | |
| 	tms->tms_cutime = cputime_to_clock_t(cutime);
 | |
| 	tms->tms_cstime = cputime_to_clock_t(cstime);
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
 | |
| {
 | |
| 	if (tbuf) {
 | |
| 		struct tms tmp;
 | |
| 
 | |
| 		do_sys_times(&tmp);
 | |
| 		if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
 | |
| 			return -EFAULT;
 | |
| 	}
 | |
| 	force_successful_syscall_return();
 | |
| 	return (long) jiffies_64_to_clock_t(get_jiffies_64());
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * This needs some heavy checking ...
 | |
|  * I just haven't the stomach for it. I also don't fully
 | |
|  * understand sessions/pgrp etc. Let somebody who does explain it.
 | |
|  *
 | |
|  * OK, I think I have the protection semantics right.... this is really
 | |
|  * only important on a multi-user system anyway, to make sure one user
 | |
|  * can't send a signal to a process owned by another.  -TYT, 12/12/91
 | |
|  *
 | |
|  * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
 | |
|  * LBT 04.03.94
 | |
|  */
 | |
| SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
 | |
| {
 | |
| 	struct task_struct *p;
 | |
| 	struct task_struct *group_leader = current->group_leader;
 | |
| 	struct pid *pgrp;
 | |
| 	int err;
 | |
| 
 | |
| 	if (!pid)
 | |
| 		pid = task_pid_vnr(group_leader);
 | |
| 	if (!pgid)
 | |
| 		pgid = pid;
 | |
| 	if (pgid < 0)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	/* From this point forward we keep holding onto the tasklist lock
 | |
| 	 * so that our parent does not change from under us. -DaveM
 | |
| 	 */
 | |
| 	write_lock_irq(&tasklist_lock);
 | |
| 
 | |
| 	err = -ESRCH;
 | |
| 	p = find_task_by_vpid(pid);
 | |
| 	if (!p)
 | |
| 		goto out;
 | |
| 
 | |
| 	err = -EINVAL;
 | |
| 	if (!thread_group_leader(p))
 | |
| 		goto out;
 | |
| 
 | |
| 	if (same_thread_group(p->real_parent, group_leader)) {
 | |
| 		err = -EPERM;
 | |
| 		if (task_session(p) != task_session(group_leader))
 | |
| 			goto out;
 | |
| 		err = -EACCES;
 | |
| 		if (p->did_exec)
 | |
| 			goto out;
 | |
| 	} else {
 | |
| 		err = -ESRCH;
 | |
| 		if (p != group_leader)
 | |
| 			goto out;
 | |
| 	}
 | |
| 
 | |
| 	err = -EPERM;
 | |
| 	if (p->signal->leader)
 | |
| 		goto out;
 | |
| 
 | |
| 	pgrp = task_pid(p);
 | |
| 	if (pgid != pid) {
 | |
| 		struct task_struct *g;
 | |
| 
 | |
| 		pgrp = find_vpid(pgid);
 | |
| 		g = pid_task(pgrp, PIDTYPE_PGID);
 | |
| 		if (!g || task_session(g) != task_session(group_leader))
 | |
| 			goto out;
 | |
| 	}
 | |
| 
 | |
| 	err = security_task_setpgid(p, pgid);
 | |
| 	if (err)
 | |
| 		goto out;
 | |
| 
 | |
| 	if (task_pgrp(p) != pgrp) {
 | |
| 		change_pid(p, PIDTYPE_PGID, pgrp);
 | |
| 		set_task_pgrp(p, pid_nr(pgrp));
 | |
| 	}
 | |
| 
 | |
| 	err = 0;
 | |
| out:
 | |
| 	/* All paths lead to here, thus we are safe. -DaveM */
 | |
| 	write_unlock_irq(&tasklist_lock);
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE1(getpgid, pid_t, pid)
 | |
| {
 | |
| 	struct task_struct *p;
 | |
| 	struct pid *grp;
 | |
| 	int retval;
 | |
| 
 | |
| 	rcu_read_lock();
 | |
| 	if (!pid)
 | |
| 		grp = task_pgrp(current);
 | |
| 	else {
 | |
| 		retval = -ESRCH;
 | |
| 		p = find_task_by_vpid(pid);
 | |
| 		if (!p)
 | |
| 			goto out;
 | |
| 		grp = task_pgrp(p);
 | |
| 		if (!grp)
 | |
| 			goto out;
 | |
| 
 | |
| 		retval = security_task_getpgid(p);
 | |
| 		if (retval)
 | |
| 			goto out;
 | |
| 	}
 | |
| 	retval = pid_vnr(grp);
 | |
| out:
 | |
| 	rcu_read_unlock();
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| #ifdef __ARCH_WANT_SYS_GETPGRP
 | |
| 
 | |
| SYSCALL_DEFINE0(getpgrp)
 | |
| {
 | |
| 	return sys_getpgid(0);
 | |
| }
 | |
| 
 | |
| #endif
 | |
| 
 | |
| SYSCALL_DEFINE1(getsid, pid_t, pid)
 | |
| {
 | |
| 	struct task_struct *p;
 | |
| 	struct pid *sid;
 | |
| 	int retval;
 | |
| 
 | |
| 	rcu_read_lock();
 | |
| 	if (!pid)
 | |
| 		sid = task_session(current);
 | |
| 	else {
 | |
| 		retval = -ESRCH;
 | |
| 		p = find_task_by_vpid(pid);
 | |
| 		if (!p)
 | |
| 			goto out;
 | |
| 		sid = task_session(p);
 | |
| 		if (!sid)
 | |
| 			goto out;
 | |
| 
 | |
| 		retval = security_task_getsid(p);
 | |
| 		if (retval)
 | |
| 			goto out;
 | |
| 	}
 | |
| 	retval = pid_vnr(sid);
 | |
| out:
 | |
| 	rcu_read_unlock();
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE0(setsid)
 | |
| {
 | |
| 	struct task_struct *group_leader = current->group_leader;
 | |
| 	struct pid *sid = task_pid(group_leader);
 | |
| 	pid_t session = pid_vnr(sid);
 | |
| 	int err = -EPERM;
 | |
| 
 | |
| 	write_lock_irq(&tasklist_lock);
 | |
| 	/* Fail if I am already a session leader */
 | |
| 	if (group_leader->signal->leader)
 | |
| 		goto out;
 | |
| 
 | |
| 	/* Fail if a process group id already exists that equals the
 | |
| 	 * proposed session id.
 | |
| 	 */
 | |
| 	if (pid_task(sid, PIDTYPE_PGID))
 | |
| 		goto out;
 | |
| 
 | |
| 	group_leader->signal->leader = 1;
 | |
| 	__set_special_pids(sid);
 | |
| 
 | |
| 	proc_clear_tty(group_leader);
 | |
| 
 | |
| 	err = session;
 | |
| out:
 | |
| 	write_unlock_irq(&tasklist_lock);
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Supplementary group IDs
 | |
|  */
 | |
| 
 | |
| /* init to 2 - one for init_task, one to ensure it is never freed */
 | |
| struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
 | |
| 
 | |
| struct group_info *groups_alloc(int gidsetsize)
 | |
| {
 | |
| 	struct group_info *group_info;
 | |
| 	int nblocks;
 | |
| 	int i;
 | |
| 
 | |
| 	nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
 | |
| 	/* Make sure we always allocate at least one indirect block pointer */
 | |
| 	nblocks = nblocks ? : 1;
 | |
| 	group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
 | |
| 	if (!group_info)
 | |
| 		return NULL;
 | |
| 	group_info->ngroups = gidsetsize;
 | |
| 	group_info->nblocks = nblocks;
 | |
| 	atomic_set(&group_info->usage, 1);
 | |
| 
 | |
| 	if (gidsetsize <= NGROUPS_SMALL)
 | |
| 		group_info->blocks[0] = group_info->small_block;
 | |
| 	else {
 | |
| 		for (i = 0; i < nblocks; i++) {
 | |
| 			gid_t *b;
 | |
| 			b = (void *)__get_free_page(GFP_USER);
 | |
| 			if (!b)
 | |
| 				goto out_undo_partial_alloc;
 | |
| 			group_info->blocks[i] = b;
 | |
| 		}
 | |
| 	}
 | |
| 	return group_info;
 | |
| 
 | |
| out_undo_partial_alloc:
 | |
| 	while (--i >= 0) {
 | |
| 		free_page((unsigned long)group_info->blocks[i]);
 | |
| 	}
 | |
| 	kfree(group_info);
 | |
| 	return NULL;
 | |
| }
 | |
| 
 | |
| EXPORT_SYMBOL(groups_alloc);
 | |
| 
 | |
| void groups_free(struct group_info *group_info)
 | |
| {
 | |
| 	if (group_info->blocks[0] != group_info->small_block) {
 | |
| 		int i;
 | |
| 		for (i = 0; i < group_info->nblocks; i++)
 | |
| 			free_page((unsigned long)group_info->blocks[i]);
 | |
| 	}
 | |
| 	kfree(group_info);
 | |
| }
 | |
| 
 | |
| EXPORT_SYMBOL(groups_free);
 | |
| 
 | |
| /* export the group_info to a user-space array */
 | |
| static int groups_to_user(gid_t __user *grouplist,
 | |
| 			  const struct group_info *group_info)
 | |
| {
 | |
| 	int i;
 | |
| 	unsigned int count = group_info->ngroups;
 | |
| 
 | |
| 	for (i = 0; i < group_info->nblocks; i++) {
 | |
| 		unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
 | |
| 		unsigned int len = cp_count * sizeof(*grouplist);
 | |
| 
 | |
| 		if (copy_to_user(grouplist, group_info->blocks[i], len))
 | |
| 			return -EFAULT;
 | |
| 
 | |
| 		grouplist += NGROUPS_PER_BLOCK;
 | |
| 		count -= cp_count;
 | |
| 	}
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /* fill a group_info from a user-space array - it must be allocated already */
 | |
| static int groups_from_user(struct group_info *group_info,
 | |
|     gid_t __user *grouplist)
 | |
| {
 | |
| 	int i;
 | |
| 	unsigned int count = group_info->ngroups;
 | |
| 
 | |
| 	for (i = 0; i < group_info->nblocks; i++) {
 | |
| 		unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
 | |
| 		unsigned int len = cp_count * sizeof(*grouplist);
 | |
| 
 | |
| 		if (copy_from_user(group_info->blocks[i], grouplist, len))
 | |
| 			return -EFAULT;
 | |
| 
 | |
| 		grouplist += NGROUPS_PER_BLOCK;
 | |
| 		count -= cp_count;
 | |
| 	}
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /* a simple Shell sort */
 | |
| static void groups_sort(struct group_info *group_info)
 | |
| {
 | |
| 	int base, max, stride;
 | |
| 	int gidsetsize = group_info->ngroups;
 | |
| 
 | |
| 	for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
 | |
| 		; /* nothing */
 | |
| 	stride /= 3;
 | |
| 
 | |
| 	while (stride) {
 | |
| 		max = gidsetsize - stride;
 | |
| 		for (base = 0; base < max; base++) {
 | |
| 			int left = base;
 | |
| 			int right = left + stride;
 | |
| 			gid_t tmp = GROUP_AT(group_info, right);
 | |
| 
 | |
| 			while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
 | |
| 				GROUP_AT(group_info, right) =
 | |
| 				    GROUP_AT(group_info, left);
 | |
| 				right = left;
 | |
| 				left -= stride;
 | |
| 			}
 | |
| 			GROUP_AT(group_info, right) = tmp;
 | |
| 		}
 | |
| 		stride /= 3;
 | |
| 	}
 | |
| }
 | |
| 
 | |
| /* a simple bsearch */
 | |
| int groups_search(const struct group_info *group_info, gid_t grp)
 | |
| {
 | |
| 	unsigned int left, right;
 | |
| 
 | |
| 	if (!group_info)
 | |
| 		return 0;
 | |
| 
 | |
| 	left = 0;
 | |
| 	right = group_info->ngroups;
 | |
| 	while (left < right) {
 | |
| 		unsigned int mid = (left+right)/2;
 | |
| 		int cmp = grp - GROUP_AT(group_info, mid);
 | |
| 		if (cmp > 0)
 | |
| 			left = mid + 1;
 | |
| 		else if (cmp < 0)
 | |
| 			right = mid;
 | |
| 		else
 | |
| 			return 1;
 | |
| 	}
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * set_groups - Change a group subscription in a set of credentials
 | |
|  * @new: The newly prepared set of credentials to alter
 | |
|  * @group_info: The group list to install
 | |
|  *
 | |
|  * Validate a group subscription and, if valid, insert it into a set
 | |
|  * of credentials.
 | |
|  */
 | |
| int set_groups(struct cred *new, struct group_info *group_info)
 | |
| {
 | |
| 	int retval;
 | |
| 
 | |
| 	retval = security_task_setgroups(group_info);
 | |
| 	if (retval)
 | |
| 		return retval;
 | |
| 
 | |
| 	put_group_info(new->group_info);
 | |
| 	groups_sort(group_info);
 | |
| 	get_group_info(group_info);
 | |
| 	new->group_info = group_info;
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| EXPORT_SYMBOL(set_groups);
 | |
| 
 | |
| /**
 | |
|  * set_current_groups - Change current's group subscription
 | |
|  * @group_info: The group list to impose
 | |
|  *
 | |
|  * Validate a group subscription and, if valid, impose it upon current's task
 | |
|  * security record.
 | |
|  */
 | |
| int set_current_groups(struct group_info *group_info)
 | |
| {
 | |
| 	struct cred *new;
 | |
| 	int ret;
 | |
| 
 | |
| 	new = prepare_creds();
 | |
| 	if (!new)
 | |
| 		return -ENOMEM;
 | |
| 
 | |
| 	ret = set_groups(new, group_info);
 | |
| 	if (ret < 0) {
 | |
| 		abort_creds(new);
 | |
| 		return ret;
 | |
| 	}
 | |
| 
 | |
| 	return commit_creds(new);
 | |
| }
 | |
| 
 | |
| EXPORT_SYMBOL(set_current_groups);
 | |
| 
 | |
| SYSCALL_DEFINE2(getgroups, int, gidsetsize, gid_t __user *, grouplist)
 | |
| {
 | |
| 	const struct cred *cred = current_cred();
 | |
| 	int i;
 | |
| 
 | |
| 	if (gidsetsize < 0)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	/* no need to grab task_lock here; it cannot change */
 | |
| 	i = cred->group_info->ngroups;
 | |
| 	if (gidsetsize) {
 | |
| 		if (i > gidsetsize) {
 | |
| 			i = -EINVAL;
 | |
| 			goto out;
 | |
| 		}
 | |
| 		if (groups_to_user(grouplist, cred->group_info)) {
 | |
| 			i = -EFAULT;
 | |
| 			goto out;
 | |
| 		}
 | |
| 	}
 | |
| out:
 | |
| 	return i;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  *	SMP: Our groups are copy-on-write. We can set them safely
 | |
|  *	without another task interfering.
 | |
|  */
 | |
|  
 | |
| SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
 | |
| {
 | |
| 	struct group_info *group_info;
 | |
| 	int retval;
 | |
| 
 | |
| 	if (!capable(CAP_SETGID))
 | |
| 		return -EPERM;
 | |
| 	if ((unsigned)gidsetsize > NGROUPS_MAX)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	group_info = groups_alloc(gidsetsize);
 | |
| 	if (!group_info)
 | |
| 		return -ENOMEM;
 | |
| 	retval = groups_from_user(group_info, grouplist);
 | |
| 	if (retval) {
 | |
| 		put_group_info(group_info);
 | |
| 		return retval;
 | |
| 	}
 | |
| 
 | |
| 	retval = set_current_groups(group_info);
 | |
| 	put_group_info(group_info);
 | |
| 
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Check whether we're fsgid/egid or in the supplemental group..
 | |
|  */
 | |
| int in_group_p(gid_t grp)
 | |
| {
 | |
| 	const struct cred *cred = current_cred();
 | |
| 	int retval = 1;
 | |
| 
 | |
| 	if (grp != cred->fsgid)
 | |
| 		retval = groups_search(cred->group_info, grp);
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| EXPORT_SYMBOL(in_group_p);
 | |
| 
 | |
| int in_egroup_p(gid_t grp)
 | |
| {
 | |
| 	const struct cred *cred = current_cred();
 | |
| 	int retval = 1;
 | |
| 
 | |
| 	if (grp != cred->egid)
 | |
| 		retval = groups_search(cred->group_info, grp);
 | |
| 	return retval;
 | |
| }
 | |
| 
 | |
| EXPORT_SYMBOL(in_egroup_p);
 | |
| 
 | |
| DECLARE_RWSEM(uts_sem);
 | |
| 
 | |
| SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
 | |
| {
 | |
| 	int errno = 0;
 | |
| 
 | |
| 	down_read(&uts_sem);
 | |
| 	if (copy_to_user(name, utsname(), sizeof *name))
 | |
| 		errno = -EFAULT;
 | |
| 	up_read(&uts_sem);
 | |
| 	return errno;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
 | |
| {
 | |
| 	int errno;
 | |
| 	char tmp[__NEW_UTS_LEN];
 | |
| 
 | |
| 	if (!capable(CAP_SYS_ADMIN))
 | |
| 		return -EPERM;
 | |
| 	if (len < 0 || len > __NEW_UTS_LEN)
 | |
| 		return -EINVAL;
 | |
| 	down_write(&uts_sem);
 | |
| 	errno = -EFAULT;
 | |
| 	if (!copy_from_user(tmp, name, len)) {
 | |
| 		struct new_utsname *u = utsname();
 | |
| 
 | |
| 		memcpy(u->nodename, tmp, len);
 | |
| 		memset(u->nodename + len, 0, sizeof(u->nodename) - len);
 | |
| 		errno = 0;
 | |
| 	}
 | |
| 	up_write(&uts_sem);
 | |
| 	return errno;
 | |
| }
 | |
| 
 | |
| #ifdef __ARCH_WANT_SYS_GETHOSTNAME
 | |
| 
 | |
| SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
 | |
| {
 | |
| 	int i, errno;
 | |
| 	struct new_utsname *u;
 | |
| 
 | |
| 	if (len < 0)
 | |
| 		return -EINVAL;
 | |
| 	down_read(&uts_sem);
 | |
| 	u = utsname();
 | |
| 	i = 1 + strlen(u->nodename);
 | |
| 	if (i > len)
 | |
| 		i = len;
 | |
| 	errno = 0;
 | |
| 	if (copy_to_user(name, u->nodename, i))
 | |
| 		errno = -EFAULT;
 | |
| 	up_read(&uts_sem);
 | |
| 	return errno;
 | |
| }
 | |
| 
 | |
| #endif
 | |
| 
 | |
| /*
 | |
|  * Only setdomainname; getdomainname can be implemented by calling
 | |
|  * uname()
 | |
|  */
 | |
| SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
 | |
| {
 | |
| 	int errno;
 | |
| 	char tmp[__NEW_UTS_LEN];
 | |
| 
 | |
| 	if (!capable(CAP_SYS_ADMIN))
 | |
| 		return -EPERM;
 | |
| 	if (len < 0 || len > __NEW_UTS_LEN)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	down_write(&uts_sem);
 | |
| 	errno = -EFAULT;
 | |
| 	if (!copy_from_user(tmp, name, len)) {
 | |
| 		struct new_utsname *u = utsname();
 | |
| 
 | |
| 		memcpy(u->domainname, tmp, len);
 | |
| 		memset(u->domainname + len, 0, sizeof(u->domainname) - len);
 | |
| 		errno = 0;
 | |
| 	}
 | |
| 	up_write(&uts_sem);
 | |
| 	return errno;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
 | |
| {
 | |
| 	if (resource >= RLIM_NLIMITS)
 | |
| 		return -EINVAL;
 | |
| 	else {
 | |
| 		struct rlimit value;
 | |
| 		task_lock(current->group_leader);
 | |
| 		value = current->signal->rlim[resource];
 | |
| 		task_unlock(current->group_leader);
 | |
| 		return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
 | |
| 	}
 | |
| }
 | |
| 
 | |
| #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
 | |
| 
 | |
| /*
 | |
|  *	Back compatibility for getrlimit. Needed for some apps.
 | |
|  */
 | |
|  
 | |
| SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
 | |
| 		struct rlimit __user *, rlim)
 | |
| {
 | |
| 	struct rlimit x;
 | |
| 	if (resource >= RLIM_NLIMITS)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	task_lock(current->group_leader);
 | |
| 	x = current->signal->rlim[resource];
 | |
| 	task_unlock(current->group_leader);
 | |
| 	if (x.rlim_cur > 0x7FFFFFFF)
 | |
| 		x.rlim_cur = 0x7FFFFFFF;
 | |
| 	if (x.rlim_max > 0x7FFFFFFF)
 | |
| 		x.rlim_max = 0x7FFFFFFF;
 | |
| 	return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
 | |
| }
 | |
| 
 | |
| #endif
 | |
| 
 | |
| SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
 | |
| {
 | |
| 	struct rlimit new_rlim, *old_rlim;
 | |
| 	int retval;
 | |
| 
 | |
| 	if (resource >= RLIM_NLIMITS)
 | |
| 		return -EINVAL;
 | |
| 	if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
 | |
| 		return -EFAULT;
 | |
| 	if (new_rlim.rlim_cur > new_rlim.rlim_max)
 | |
| 		return -EINVAL;
 | |
| 	old_rlim = current->signal->rlim + resource;
 | |
| 	if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
 | |
| 	    !capable(CAP_SYS_RESOURCE))
 | |
| 		return -EPERM;
 | |
| 	if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open)
 | |
| 		return -EPERM;
 | |
| 
 | |
| 	retval = security_task_setrlimit(resource, &new_rlim);
 | |
| 	if (retval)
 | |
| 		return retval;
 | |
| 
 | |
| 	if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) {
 | |
| 		/*
 | |
| 		 * The caller is asking for an immediate RLIMIT_CPU
 | |
| 		 * expiry.  But we use the zero value to mean "it was
 | |
| 		 * never set".  So let's cheat and make it one second
 | |
| 		 * instead
 | |
| 		 */
 | |
| 		new_rlim.rlim_cur = 1;
 | |
| 	}
 | |
| 
 | |
| 	task_lock(current->group_leader);
 | |
| 	*old_rlim = new_rlim;
 | |
| 	task_unlock(current->group_leader);
 | |
| 
 | |
| 	if (resource != RLIMIT_CPU)
 | |
| 		goto out;
 | |
| 
 | |
| 	/*
 | |
| 	 * RLIMIT_CPU handling.   Note that the kernel fails to return an error
 | |
| 	 * code if it rejected the user's attempt to set RLIMIT_CPU.  This is a
 | |
| 	 * very long-standing error, and fixing it now risks breakage of
 | |
| 	 * applications, so we live with it
 | |
| 	 */
 | |
| 	if (new_rlim.rlim_cur == RLIM_INFINITY)
 | |
| 		goto out;
 | |
| 
 | |
| 	update_rlimit_cpu(new_rlim.rlim_cur);
 | |
| out:
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * It would make sense to put struct rusage in the task_struct,
 | |
|  * except that would make the task_struct be *really big*.  After
 | |
|  * task_struct gets moved into malloc'ed memory, it would
 | |
|  * make sense to do this.  It will make moving the rest of the information
 | |
|  * a lot simpler!  (Which we're not doing right now because we're not
 | |
|  * measuring them yet).
 | |
|  *
 | |
|  * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
 | |
|  * races with threads incrementing their own counters.  But since word
 | |
|  * reads are atomic, we either get new values or old values and we don't
 | |
|  * care which for the sums.  We always take the siglock to protect reading
 | |
|  * the c* fields from p->signal from races with exit.c updating those
 | |
|  * fields when reaping, so a sample either gets all the additions of a
 | |
|  * given child after it's reaped, or none so this sample is before reaping.
 | |
|  *
 | |
|  * Locking:
 | |
|  * We need to take the siglock for CHILDEREN, SELF and BOTH
 | |
|  * for  the cases current multithreaded, non-current single threaded
 | |
|  * non-current multithreaded.  Thread traversal is now safe with
 | |
|  * the siglock held.
 | |
|  * Strictly speaking, we donot need to take the siglock if we are current and
 | |
|  * single threaded,  as no one else can take our signal_struct away, no one
 | |
|  * else can  reap the  children to update signal->c* counters, and no one else
 | |
|  * can race with the signal-> fields. If we do not take any lock, the
 | |
|  * signal-> fields could be read out of order while another thread was just
 | |
|  * exiting. So we should  place a read memory barrier when we avoid the lock.
 | |
|  * On the writer side,  write memory barrier is implied in  __exit_signal
 | |
|  * as __exit_signal releases  the siglock spinlock after updating the signal->
 | |
|  * fields. But we don't do this yet to keep things simple.
 | |
|  *
 | |
|  */
 | |
| 
 | |
| static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
 | |
| {
 | |
| 	r->ru_nvcsw += t->nvcsw;
 | |
| 	r->ru_nivcsw += t->nivcsw;
 | |
| 	r->ru_minflt += t->min_flt;
 | |
| 	r->ru_majflt += t->maj_flt;
 | |
| 	r->ru_inblock += task_io_get_inblock(t);
 | |
| 	r->ru_oublock += task_io_get_oublock(t);
 | |
| }
 | |
| 
 | |
| static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 | |
| {
 | |
| 	struct task_struct *t;
 | |
| 	unsigned long flags;
 | |
| 	cputime_t utime, stime;
 | |
| 	struct task_cputime cputime;
 | |
| 
 | |
| 	memset((char *) r, 0, sizeof *r);
 | |
| 	utime = stime = cputime_zero;
 | |
| 
 | |
| 	if (who == RUSAGE_THREAD) {
 | |
| 		utime = task_utime(current);
 | |
| 		stime = task_stime(current);
 | |
| 		accumulate_thread_rusage(p, r);
 | |
| 		goto out;
 | |
| 	}
 | |
| 
 | |
| 	if (!lock_task_sighand(p, &flags))
 | |
| 		return;
 | |
| 
 | |
| 	switch (who) {
 | |
| 		case RUSAGE_BOTH:
 | |
| 		case RUSAGE_CHILDREN:
 | |
| 			utime = p->signal->cutime;
 | |
| 			stime = p->signal->cstime;
 | |
| 			r->ru_nvcsw = p->signal->cnvcsw;
 | |
| 			r->ru_nivcsw = p->signal->cnivcsw;
 | |
| 			r->ru_minflt = p->signal->cmin_flt;
 | |
| 			r->ru_majflt = p->signal->cmaj_flt;
 | |
| 			r->ru_inblock = p->signal->cinblock;
 | |
| 			r->ru_oublock = p->signal->coublock;
 | |
| 
 | |
| 			if (who == RUSAGE_CHILDREN)
 | |
| 				break;
 | |
| 
 | |
| 		case RUSAGE_SELF:
 | |
| 			thread_group_cputime(p, &cputime);
 | |
| 			utime = cputime_add(utime, cputime.utime);
 | |
| 			stime = cputime_add(stime, cputime.stime);
 | |
| 			r->ru_nvcsw += p->signal->nvcsw;
 | |
| 			r->ru_nivcsw += p->signal->nivcsw;
 | |
| 			r->ru_minflt += p->signal->min_flt;
 | |
| 			r->ru_majflt += p->signal->maj_flt;
 | |
| 			r->ru_inblock += p->signal->inblock;
 | |
| 			r->ru_oublock += p->signal->oublock;
 | |
| 			t = p;
 | |
| 			do {
 | |
| 				accumulate_thread_rusage(t, r);
 | |
| 				t = next_thread(t);
 | |
| 			} while (t != p);
 | |
| 			break;
 | |
| 
 | |
| 		default:
 | |
| 			BUG();
 | |
| 	}
 | |
| 	unlock_task_sighand(p, &flags);
 | |
| 
 | |
| out:
 | |
| 	cputime_to_timeval(utime, &r->ru_utime);
 | |
| 	cputime_to_timeval(stime, &r->ru_stime);
 | |
| }
 | |
| 
 | |
| int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
 | |
| {
 | |
| 	struct rusage r;
 | |
| 	k_getrusage(p, who, &r);
 | |
| 	return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
 | |
| {
 | |
| 	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
 | |
| 	    who != RUSAGE_THREAD)
 | |
| 		return -EINVAL;
 | |
| 	return getrusage(current, who, ru);
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE1(umask, int, mask)
 | |
| {
 | |
| 	mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
 | |
| 	return mask;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 | |
| 		unsigned long, arg4, unsigned long, arg5)
 | |
| {
 | |
| 	struct task_struct *me = current;
 | |
| 	unsigned char comm[sizeof(me->comm)];
 | |
| 	long error;
 | |
| 
 | |
| 	error = security_task_prctl(option, arg2, arg3, arg4, arg5);
 | |
| 	if (error != -ENOSYS)
 | |
| 		return error;
 | |
| 
 | |
| 	error = 0;
 | |
| 	switch (option) {
 | |
| 		case PR_SET_PDEATHSIG:
 | |
| 			if (!valid_signal(arg2)) {
 | |
| 				error = -EINVAL;
 | |
| 				break;
 | |
| 			}
 | |
| 			me->pdeath_signal = arg2;
 | |
| 			error = 0;
 | |
| 			break;
 | |
| 		case PR_GET_PDEATHSIG:
 | |
| 			error = put_user(me->pdeath_signal, (int __user *)arg2);
 | |
| 			break;
 | |
| 		case PR_GET_DUMPABLE:
 | |
| 			error = get_dumpable(me->mm);
 | |
| 			break;
 | |
| 		case PR_SET_DUMPABLE:
 | |
| 			if (arg2 < 0 || arg2 > 1) {
 | |
| 				error = -EINVAL;
 | |
| 				break;
 | |
| 			}
 | |
| 			set_dumpable(me->mm, arg2);
 | |
| 			error = 0;
 | |
| 			break;
 | |
| 
 | |
| 		case PR_SET_UNALIGN:
 | |
| 			error = SET_UNALIGN_CTL(me, arg2);
 | |
| 			break;
 | |
| 		case PR_GET_UNALIGN:
 | |
| 			error = GET_UNALIGN_CTL(me, arg2);
 | |
| 			break;
 | |
| 		case PR_SET_FPEMU:
 | |
| 			error = SET_FPEMU_CTL(me, arg2);
 | |
| 			break;
 | |
| 		case PR_GET_FPEMU:
 | |
| 			error = GET_FPEMU_CTL(me, arg2);
 | |
| 			break;
 | |
| 		case PR_SET_FPEXC:
 | |
| 			error = SET_FPEXC_CTL(me, arg2);
 | |
| 			break;
 | |
| 		case PR_GET_FPEXC:
 | |
| 			error = GET_FPEXC_CTL(me, arg2);
 | |
| 			break;
 | |
| 		case PR_GET_TIMING:
 | |
| 			error = PR_TIMING_STATISTICAL;
 | |
| 			break;
 | |
| 		case PR_SET_TIMING:
 | |
| 			if (arg2 != PR_TIMING_STATISTICAL)
 | |
| 				error = -EINVAL;
 | |
| 			else
 | |
| 				error = 0;
 | |
| 			break;
 | |
| 
 | |
| 		case PR_SET_NAME:
 | |
| 			comm[sizeof(me->comm)-1] = 0;
 | |
| 			if (strncpy_from_user(comm, (char __user *)arg2,
 | |
| 					      sizeof(me->comm) - 1) < 0)
 | |
| 				return -EFAULT;
 | |
| 			set_task_comm(me, comm);
 | |
| 			return 0;
 | |
| 		case PR_GET_NAME:
 | |
| 			get_task_comm(comm, me);
 | |
| 			if (copy_to_user((char __user *)arg2, comm,
 | |
| 					 sizeof(comm)))
 | |
| 				return -EFAULT;
 | |
| 			return 0;
 | |
| 		case PR_GET_ENDIAN:
 | |
| 			error = GET_ENDIAN(me, arg2);
 | |
| 			break;
 | |
| 		case PR_SET_ENDIAN:
 | |
| 			error = SET_ENDIAN(me, arg2);
 | |
| 			break;
 | |
| 
 | |
| 		case PR_GET_SECCOMP:
 | |
| 			error = prctl_get_seccomp();
 | |
| 			break;
 | |
| 		case PR_SET_SECCOMP:
 | |
| 			error = prctl_set_seccomp(arg2);
 | |
| 			break;
 | |
| 		case PR_GET_TSC:
 | |
| 			error = GET_TSC_CTL(arg2);
 | |
| 			break;
 | |
| 		case PR_SET_TSC:
 | |
| 			error = SET_TSC_CTL(arg2);
 | |
| 			break;
 | |
| 		case PR_GET_TIMERSLACK:
 | |
| 			error = current->timer_slack_ns;
 | |
| 			break;
 | |
| 		case PR_SET_TIMERSLACK:
 | |
| 			if (arg2 <= 0)
 | |
| 				current->timer_slack_ns =
 | |
| 					current->default_timer_slack_ns;
 | |
| 			else
 | |
| 				current->timer_slack_ns = arg2;
 | |
| 			error = 0;
 | |
| 			break;
 | |
| 		default:
 | |
| 			error = -EINVAL;
 | |
| 			break;
 | |
| 	}
 | |
| 	return error;
 | |
| }
 | |
| 
 | |
| SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
 | |
| 		struct getcpu_cache __user *, unused)
 | |
| {
 | |
| 	int err = 0;
 | |
| 	int cpu = raw_smp_processor_id();
 | |
| 	if (cpup)
 | |
| 		err |= put_user(cpu, cpup);
 | |
| 	if (nodep)
 | |
| 		err |= put_user(cpu_to_node(cpu), nodep);
 | |
| 	return err ? -EFAULT : 0;
 | |
| }
 | |
| 
 | |
| char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
 | |
| 
 | |
| static void argv_cleanup(char **argv, char **envp)
 | |
| {
 | |
| 	argv_free(argv);
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * orderly_poweroff - Trigger an orderly system poweroff
 | |
|  * @force: force poweroff if command execution fails
 | |
|  *
 | |
|  * This may be called from any context to trigger a system shutdown.
 | |
|  * If the orderly shutdown fails, it will force an immediate shutdown.
 | |
|  */
 | |
| int orderly_poweroff(bool force)
 | |
| {
 | |
| 	int argc;
 | |
| 	char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
 | |
| 	static char *envp[] = {
 | |
| 		"HOME=/",
 | |
| 		"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
 | |
| 		NULL
 | |
| 	};
 | |
| 	int ret = -ENOMEM;
 | |
| 	struct subprocess_info *info;
 | |
| 
 | |
| 	if (argv == NULL) {
 | |
| 		printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
 | |
| 		       __func__, poweroff_cmd);
 | |
| 		goto out;
 | |
| 	}
 | |
| 
 | |
| 	info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC);
 | |
| 	if (info == NULL) {
 | |
| 		argv_free(argv);
 | |
| 		goto out;
 | |
| 	}
 | |
| 
 | |
| 	call_usermodehelper_setcleanup(info, argv_cleanup);
 | |
| 
 | |
| 	ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
 | |
| 
 | |
|   out:
 | |
| 	if (ret && force) {
 | |
| 		printk(KERN_WARNING "Failed to start orderly shutdown: "
 | |
| 		       "forcing the issue\n");
 | |
| 
 | |
| 		/* I guess this should try to kick off some daemon to
 | |
| 		   sync and poweroff asap.  Or not even bother syncing
 | |
| 		   if we're doing an emergency shutdown? */
 | |
| 		emergency_sync();
 | |
| 		kernel_power_off();
 | |
| 	}
 | |
| 
 | |
| 	return ret;
 | |
| }
 | |
| EXPORT_SYMBOL_GPL(orderly_poweroff);
 |